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I I I I I I I ","" I " I I- I I I I I I I I I I approximately 2800 miles, within the total 8,000 miles of unmapped floodplains stalewide, TW8nty p8rr:Bnt of th8 fBSpond8nts b8118VB that th8/r noodpla/n maps fl8fJd to b8 updatBd, Much of Ihe data and maps were developed in the early 1970's and are lacking delail in many ways, The need to update this data is critical to successfully design for current development patterns, plan for future development activities and prepare for the 21st century. Many communities cited a lack of technical expertise as a key problem in helping to plan and implement stream corridor improvements or stabilization, With man's increased pressure to utilize floodplains and stream corridors for other uses, the need to accurately predict where certain levels of flow will reach becomes imperative to insure human and natural uses do not conflict Man's presence must accommodale Ihe stream's need 10 also occupy port'ons of the floodplain, since flood waters exercise a very real presence with no opportunity for negotiation, In addition, the responses indicated a need for educaling administrato" and landowners on Ihe principles of floodplain management. Policy and Cr~e~a: Several definitions need to be added to the current stalutory language for floodplain management aClivities, These include defining the 'base flood' for Ihe stale floodplain management activities as Ihal flood event w'th a 100'year return frequency (1 % chance), This 1 OO'year definilion 's current'y the slate's regulalory design crileria, II is recommended Ihal'crilical facilities' be protecled from losses by a 500'year return frequency (0,2% chance), 'Cr'ticalfacililies' should be defined as facilities necessary to maintain the health and safety of the public in a community, except for public road syslems, In addition, a statewide flood detention policy shouid be proposed, requiring Ihat increased storm runoff from new development activities shall be delained and standards shouid be provided for how that should be accomplished, This action will requ're establishment of a 'baseline hydrologic condition' for the state's basins/watersheds. There is also a need to create a wetland banking/accounting and replacement program to assist in maintaining existing wetland conditions. The banking system would protect the state's existing leve' of wetlands and provide opportunities for the better management of future development activities, 78%01 respooOOnts do nol have a drainage cfileriamanual IXolh8f -,'" drainage designcnleria S8VBnty-B/ght p8rr:Bnt of th8 fBSpond8nts do not haVB a dralnag8 crit8rta manual or other adoptBd dralnag8 dos/gn crlt8rta, In addition, seventy'four percent of the respondents stated that they do not have a slormwater detention policy, THE BOTTOM LINE? Aood Protection There is a clear need for improved floodplain management to reduce the aHisk human population's vulnerability to flooding and prevent further encroachment into flood hazard zones by man, There is also a need to improve stream maintenance and implement flood protection measures to reduce annual flood losses, Section VI . 5